The central focus of laboratory core 9004 is to apply the in vitro Human Tumor Clonogenic Assay (HTCA) to aid in new anticancer drug development by the laboratory and clinical project investigators in this program project and for correlation with clinical trials. Drugs studied in HTCA include cytotoxic agents, chemosensitizers growth factors, growth factor antagonists and other biologics. HTCA is conducted primarily with fresh human tumors from biopsy specimens in order to gain information of potential in vivo relevance to new drug development, and to aid in drug selection for advancement to clinical trials and to identify desirable dosing schedules and plasma concentrations to be achieved in phase I clinical trials. Additionally, HTCA may aid in identification of tumor types and specific drug sensitive for recruitment into phase II trials of specific new agents tested. Other related studies are carried out with established human tumor cell lines which are also used in quality control for standardization of HTCA. Thus this laboratory core resource supports research activities of all projects investigators in this program project.